Files
google-apis-rs/bytes/index.html
2021-04-02 00:20:57 +08:00

63 lines
8.9 KiB
HTML
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="API documentation for the Rust `bytes` crate."><meta name="keywords" content="rust, rustlang, rust-lang, bytes"><title>bytes - Rust</title><link rel="stylesheet" type="text/css" href="../normalize.css"><link rel="stylesheet" type="text/css" href="../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" type="text/css" href="../light.css" id="themeStyle"><link rel="stylesheet" type="text/css" href="../dark.css" disabled ><link rel="stylesheet" type="text/css" href="../ayu.css" disabled ><script id="default-settings"></script><script src="../storage.js"></script><noscript><link rel="stylesheet" href="../noscript.css"></noscript><link rel="icon" type="image/svg+xml" href="../favicon.svg">
<link rel="alternate icon" type="image/png" href="../favicon-16x16.png">
<link rel="alternate icon" type="image/png" href="../favicon-32x32.png"><style type="text/css">#crate-search{background-image:url("../down-arrow.svg");}</style></head><body class="rustdoc mod"><!--[if lte IE 8]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><div class="sidebar-menu">&#9776;</div><a href='../bytes/index.html'><div class='logo-container rust-logo'><img src='../rust-logo.png' alt='logo'></div></a><p class="location">Crate bytes</p><div class="block version"><p>Version 1.0.1</p></div><div class="sidebar-elems"><a id="all-types" href="all.html"><p>See all bytes's items</p></a><div class="block items"><ul><li><a href="#modules">Modules</a></li><li><a href="#structs">Structs</a></li><li><a href="#traits">Traits</a></li></ul></div><p class="location"></p><div id="sidebar-vars" data-name="bytes" data-ty="mod" data-relpath="../"></div></div></nav><div class="theme-picker"><button id="theme-picker" aria-label="Pick another theme!" aria-haspopup="menu"><img src="../brush.svg" width="18" alt="Pick another theme!"></button><div id="theme-choices" role="menu"></div></div><script src="../theme.js"></script><nav class="sub"><form class="search-form"><div class="search-container"><div><select id="crate-search"><option value="All crates">All crates</option></select><input class="search-input" name="search" disabled autocomplete="off" spellcheck="false" placeholder="Click or press S to search, ? for more options…" type="search"></div><button type="button" class="help-button">?</button>
<a id="settings-menu" href="../settings.html"><img src="../wheel.svg" width="18" alt="Change settings"></a></div></form></nav><section id="main" class="content"><h1 class="fqn"><span class="in-band">Crate <a class="mod" href="">bytes</a></span><span class="out-of-band"><span id="render-detail"><a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">[<span class="inner">&#x2212;</span>]</a></span><a class="srclink" href="../src/bytes/lib.rs.html#1-117" title="goto source code">[src]</a></span></h1><div class="docblock"><p>Provides abstractions for working with bytes.</p>
<p>The <code>bytes</code> crate provides an efficient byte buffer structure
(<a href="struct.Bytes.html"><code>Bytes</code></a>) and traits for working with buffer
implementations (<a href="trait.Buf.html"><code>Buf</code></a>, <a href="trait.BufMut.html"><code>BufMut</code></a>).</p>
<h1 id="bytes" class="section-header"><a href="#bytes"><code>Bytes</code></a></h1>
<p><code>Bytes</code> is an efficient container for storing and operating on contiguous
slices of memory. It is intended for use primarily in networking code, but
could have applications elsewhere as well.</p>
<p><code>Bytes</code> values facilitate zero-copy network programming by allowing multiple
<code>Bytes</code> objects to point to the same underlying memory. This is managed by
using a reference count to track when the memory is no longer needed and can
be freed.</p>
<p>A <code>Bytes</code> handle can be created directly from an existing byte store (such as <code>&amp;[u8]</code>
or <code>Vec&lt;u8&gt;</code>), but usually a <code>BytesMut</code> is used first and written to. For
example:</p>
<div class="example-wrap"><pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">bytes</span>::{<span class="ident">BytesMut</span>, <span class="ident">BufMut</span>};
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">buf</span> <span class="op">=</span> <span class="ident">BytesMut</span>::<span class="ident">with_capacity</span>(<span class="number">1024</span>);
<span class="ident">buf</span>.<span class="ident">put</span>(<span class="kw-2">&amp;</span><span class="string">b&quot;hello world&quot;</span>[..]);
<span class="ident">buf</span>.<span class="ident">put_u16</span>(<span class="number">1234</span>);
<span class="kw">let</span> <span class="ident">a</span> <span class="op">=</span> <span class="ident">buf</span>.<span class="ident">split</span>();
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">a</span>, <span class="string">b&quot;hello world\x04\xD2&quot;</span>[..]);
<span class="ident">buf</span>.<span class="ident">put</span>(<span class="kw-2">&amp;</span><span class="string">b&quot;goodbye world&quot;</span>[..]);
<span class="kw">let</span> <span class="ident">b</span> <span class="op">=</span> <span class="ident">buf</span>.<span class="ident">split</span>();
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">b</span>, <span class="string">b&quot;goodbye world&quot;</span>[..]);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">buf</span>.<span class="ident">capacity</span>(), <span class="number">998</span>);</pre></div>
<p>In the above example, only a single buffer of 1024 is allocated. The handles
<code>a</code> and <code>b</code> will share the underlying buffer and maintain indices tracking
the view into the buffer represented by the handle.</p>
<p>See the <a href="struct.Bytes.html">struct docs</a> for more details.</p>
<h1 id="buf-bufmut" class="section-header"><a href="#buf-bufmut"><code>Buf</code>, <code>BufMut</code></a></h1>
<p>These two traits provide read and write access to buffers. The underlying
storage may or may not be in contiguous memory. For example, <code>Bytes</code> is a
buffer that guarantees contiguous memory, but a <a href="https://en.wikipedia.org/wiki/Rope_(data_structure)">rope</a> stores the bytes in
disjoint chunks. <code>Buf</code> and <code>BufMut</code> maintain cursors tracking the current
position in the underlying byte storage. When bytes are read or written, the
cursor is advanced.</p>
<h2 id="relation-with-read-and-write" class="section-header"><a href="#relation-with-read-and-write">Relation with <code>Read</code> and <code>Write</code></a></h2>
<p>At first glance, it may seem that <code>Buf</code> and <code>BufMut</code> overlap in
functionality with <code>std::io::Read</code> and <code>std::io::Write</code>. However, they
serve different purposes. A buffer is the value that is provided as an
argument to <code>Read::read</code> and <code>Write::write</code>. <code>Read</code> and <code>Write</code> may then
perform a syscall, which has the potential of failing. Operations on <code>Buf</code>
and <code>BufMut</code> are infallible.</p>
</div><h2 id="modules" class="section-header"><a href="#modules">Modules</a></h2>
<table><tr class="module-item"><td><a class="mod" href="buf/index.html" title="bytes::buf mod">buf</a></td><td class="docblock-short"><p>Utilities for working with buffers.</p>
</td></tr></table><h2 id="structs" class="section-header"><a href="#structs">Structs</a></h2>
<table><tr class="module-item"><td><a class="struct" href="struct.Bytes.html" title="bytes::Bytes struct">Bytes</a></td><td class="docblock-short"><p>A cheaply cloneable and sliceable chunk of contiguous memory.</p>
</td></tr><tr class="module-item"><td><a class="struct" href="struct.BytesMut.html" title="bytes::BytesMut struct">BytesMut</a></td><td class="docblock-short"><p>A unique reference to a contiguous slice of memory.</p>
</td></tr></table><h2 id="traits" class="section-header"><a href="#traits">Traits</a></h2>
<table><tr class="module-item"><td><a class="trait" href="trait.Buf.html" title="bytes::Buf trait">Buf</a></td><td class="docblock-short"><p>Read bytes from a buffer.</p>
</td></tr><tr class="module-item"><td><a class="trait" href="trait.BufMut.html" title="bytes::BufMut trait">BufMut</a></td><td class="docblock-short"><p>A trait for values that provide sequential write access to bytes.</p>
</td></tr></table></section><section id="search" class="content hidden"></section><section class="footer"></section><div id="rustdoc-vars" data-root-path="../" data-current-crate="bytes"></div>
<script src="../main.js"></script><script defer src="../search-index.js"></script></body></html>